This thesis sets out to investigate relevance-theoretic pragmatics and its contribution to the study of linguistic meaning from a mentalist outlook. Adopting an internalist perspective with respect to the semantics of language seems to create serious problems for traditional accounts, which customarily seek to separate some common core of meaning from contextualisation. Against this background, it is argued that the ways in which an individual's mentally represented linguistic meanings are pervasively affected by his system of beliefs can be realistically addressed from a cognitive point of view through the implementation of the proposals of Relevance Theory regarding the inferential processes involved in the interpretation of utterances. In this setting, linguistic meaning is always provided through inference against the context of utterance and the need for a stable semantic content that is identical across individuals largely evaporates. In pursuit of this argument, the existing account of context within the relevance-theoretic framework is initially reviewed and extended. Then, on the basis of current research on the human cognitive capacity for metarepresentation and joint attention, it is suggested that it is an innate predisposition which enables us to efficiently align our contexts in instances of communication. In addition, it is argued that these highly developed mind-reading abilities are partially responsible for our natural tendency to develop an understanding of the world which closely resembles that of our peers; a point further elucidated by reference to Searle's notion of the Background. Finally, the semantics/pragmatics distinction is readdressed from a cognitive perspective and a case is made for the substitution of the externalist theory of semantic content with a more psychologically plausible contextualist counterpart within Relevance Theory itself.